Model data of a three-dimensional object disposed in three-dimensional virtual space corresponding to real space is displayed in a manner superimposed on a photographed image captured by an imaging apparatus. This technology augments information collected by a human perception (such as vision), and is accordingly referred to as augmented reality (AR) or the like. The model data of a three-dimensional object disposed in three-dimensional virtual space corresponding to real space is referred to as an AR content.
A projection image of the AR content of which the position on virtual space corresponding to real space is set, is displayed in a manner superimposed on a photographed image based on the position on virtual space. Note that the projection image of the AR content is further generated based on a positional relation between an imaging apparatus and the AR content.
In order to determine a positional relation between the imaging apparatus and the AR content, a reference object is employed. For example, an AR marker is generally employed as the reference object. Specifically, upon an AR marker being detected from a photographed image photographed by the imaging apparatus, the positional relation between the AR marker and the imaging apparatus is determined based on an image of the AR marker reflected in the photographed image of the imaging apparatus. The projection image of the AR content corresponding to the AR marker is displayed in a manner superimposed on the photographed image in which the positional relation is reflected. For example, there are disclosed techniques relating to Japanese National Publication of International Patent Application No. 2010-531089, and International Publication Pamphlet No. WO 2005-119539. AR technology has recently been employed for various fields. For example, AR technology is employed for a system supporting a worker who performs work within a facility.
On the other hand, there is technology using an IC tag to determine the legitimacy of a worker performing work. For example, there is an entrance and exit management server configured to determine the legitimacy of an IC-tag holder, based on position and time and so forth at the time of reading the IC tag. An example of this entrance and exit management server is disclosed in Japanese Laid-open Patent Publication No. 2007-323141. This entrance and exit management server outputs an alarm regarding whether or not an IC-tag holder is in an appropriate workplace. This determination is made based on determination regarding whether or not the number of a gate which has read the IC tag is included in the number of a reading gate installed in a workplace associated with a user who possesses this IC tag. Also, the entrance and exit management server calculates the duration of the worker's stay, and also determines the legitimacy of the worker based on whether or not the duration of the stay is normal.